Gun



Jan. 2l, 1930. .1. l.. HATCHER GUN Filed July 25. 1927 wuwto/c dan-LEE L1. Hatcher Patented Jan. 21, 1930 JAMES L. HATCHER, 0F THE UNITED STATES ARMY, WIN CHESTER, VIRGINIA GUN Application filed July 25, 1927. Serial No. 208,312.

(GRANTED UNDER THE ACT 0F MARCH 3, 1883 The invention described herein may be manufactured and used by or for the Government for governmental purposes Without the payment to me of any royalty thereon.

lThis invention relates to guns and more specifically it has reference to means for automatically locking and unlocking the breech closure of a gun barrel.

Breech locks of the type wherein the locking action is effected by the inter-engagement of the block and barrel have been designed for automatic pistols Whose ammunition develops a pressure Which is less than 1/3 the pressure developed in rifles. In all of these devices the barrel has a longitudinal and in some cases also a rotational movement.

Because of the low pressures en'lployed it has been unnecessary to give consideration to opposing the unlocking action of the breech bolt except by the Weight of the members.

The breech block of the present invention is intended for guns wherein a. high pressure is developed and accordingly it is proposed to hold the barrel against longitudinal displacement While permitting rotary movement thereof and to actively oppose the unlocking action of the breech bolt by reason of having the unlocking rotary movement of the barrel in the direction of the riding of the barrel, and also, if desired, by auxiliary means.

With the foregoing and other objects in View, my invention resides in the novel arrangement and combination of parts and in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment of the invention herein disclosed may be made within the scope of what is claimed Without departing from the spirit of the invention.

A practical embodiment of the invention is illustrated in the accompanying drawing, wherein:

Fig. l is a fragmentary plan view of a gun partly in section, showing the bolt in locked position;

Figs. 2, 3 and 4f are detail sectional views taken on the respective lines of Fig. 1;

Fig. 5 is a view similar to Fig. 1 showing the bolt in its initial stage of recoil and unlocked from the barrel;

AS AMENDED APRIL 30, 1928; 370 0. G. 757) Fig. 6 is a detail sectional vieiv of the barrel With the bolt in locked position;

F ig. 7 is a detail view on the line 7-7 of F ig. 5.

Referring to the drawings by numerals of reference rlhe invention is illustrated in connection With a rifle which consists of the usual stock 5, a frame or receiver 6, barrel 7, and breech bolt 8. The receiver is provided With a rear gg bearing 9 and a front bearing 10 in Which the barrel is rotationally mounted. The rear end of the barrel abuts against a shoulder l1 formed in the receiver and is provided with a collar 12 abutting the forward bearing; this provision serving to prevent longitudinal movement of the barrel. The receiver, in rear of the barrel, is formed ivith grooves 13 for receiving the guides 14 on the bolt Whereby the bolt is constrained to rectilinear move ment during recoil and counter recoil.

rlhe forward portion of the bolt carries a pair of cam pins 15 arranged to enter obliquely-disposed cam slots 16 in the rear of the barrel so that, as seen in Fig. 1, when the bolt is moved in recoil, due to the force of the eX- plosion, the barrel is rotated to the left and assumes the position shown in Fig. 5 when the pins have cleared the cam slots.

In order that the unlocking action may, a when desirable, be opposed by a force in addition to the inertia of thebarrei, there is provided a torsion spring 17 embracing the barrel and having its ends secured to the barrel and receiver. This spring tends to move the barrel to the right augmenting the torsional force produced by the bullet in traveling along a barrel Whose rifling 18 is left handed.

For the purpose of holding the barrel in the position to which it has been rotated during retraction of the bolt there is mounted in the receiver a plunger 19 which will enter one of the cam slots as the cam pin is leaving that slot as seen in Fig. 7. On the connterrecoil stroke of the breech bolt the cam pin on entering the cam slot will accordingly raise the plunger until it is disengaged from the barrel.

The arrangement herein shown will permit a comparatively light return spring (not rm e.

engageable in shown) to be employed as a considerable amount of the energy of recoil Will be absorbed in the unlocking action. Likewise the action of locking will result in the expenditure of energy of thereturn spring permitting the bolt to 'be eased into battery.Y It desired the return and torque springsv may be balanced in such a manner as to allovv the latter to assist in'and complete the locking movement of the breech bolt.

While the invention in connection With a rifle it is not limited thereto and may be practiced in other classes of lirearms. v

I claim:

l. In a gun, a receiver, a rifled barrel mounted therein for limited rotary movement, a breach bolt reciprocally mounted in the receiver, cooperating means on the bolt and barrel for rotating the barrel, a torsion spring acting in the direction of the rifling for opposing barrel and means for holding the barrel against movement when the breech bolt is a separated from the barrel, said means arranged to be released by the breech bolt.

2. In a gun, a receiver, a rifled Vbarrel mounted therein for limited rotary movement, a breech bolt reciprocally mounted in the receiver, cooperating means on the bolt and barrel for rotating the barrel, a torsion spring acting in the direction of the rifling for opposing the unlocking movement of the barrel and means for holding the barrel against movement When the breech bolt is separated from theV barrel.

3. In a gun, a receiver, a riled barrel mounted therein Jfor limited rotary movement, a breech bolt reciprocally mounted in the receiver, cooperating means on the bolt and barrel for rotating the barrel, means acting in the direction of the rifling for opposing the unlocking movement of the barrel andA means for holding the barrel against movement when the breech bolt is separated from the barrel.

4. In a gun, a receiver, a non-recoiling barrelmounted therein for limited rotary movement, a breech bolt reciprocally mounted in the receiver, cooperating means on the bolt and barrel for rotating the barrel, resilient means for opposing the unlocking movement of the barrel and means for holding the barrel against movement when the breech bolt is separated from the barrel.

5. In a gun, a receiver, a barrel mounted therein for rotary movement and Jformed With inclined cam slots open at the rear edge of the barrel, a breech bolt reciprocally mounted in the receiver, cam pins on the bolt the cam slots of the barrel, and means carried by the receiver Vand engageable in one of the cam slots to lhold the barrel against movement When the breech boltv is 'separated :trom the barrel.

the unlocking movement of the cally mounted in a receiver and camv pins on the bolt engageablein the cam `slots of the barrel.

,JAMES HATCI-IER.

has been illustratec' 

